#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
 
int main(int argc, char **argv)
{
        int fd;
        int val=1;
        fd = open("/dev/embeded_led", O_RDWR);        //打开设备
        if(fd < 0)
            printf("can`t open!\n");
        if(argc != 2)
        {
                printf("Usage :\n");
                printf("%s <on|off>\n", argv[0]);
                return 0;
        }
 
        if (strcmp(argv[1], "on") == 0)
        {
                val  = 1;
        }
        else
        {
                val = 0;
        }
        write(fd, &val, 4);
        return 0;
}
